Abstract: Abstract：The Putaohua reservoir in 1st Member of Yaojia Formation within Sanzhao depression is the main reservoir, oil layer and also the important target reservoir for increasing production in the study area. The distribution of the reservoir has intimate relationship with the source, and hence the source system analysis is an important task in petroleum exploration. Based on core observation and description as well as a comprehensive study of the analytical data, the authors analyzed the source direction in terms of heavy mineral assemblage, ZTR index variation characteristics, regional distribution of mudstone color and features of sand distribution. The source system for Putaohua reservoir in 1st Member of Yaojia Formation within Sanzhao depression was determined, and the affected area and intensity variations of each source were comprehensively analyzed and determined. The results have laid a good foundation for precise study of the sedimentary system and prediction of the reservoir.